""" 
CSDN : heart_6662
PYTHON amateur   
"""
for a in ['x','y','z']:
    for b in ['x','y','z']:
        for c in ['x','y','z']:
            if a!='x' and c!='x' and c!='z' and a!=b and b!=c and c!=a:

                print("a和%s比，b和%s比，c和%s比"%(a,b,c))